By Adam Wilmoth Energy Editor awilmoth@oklahoman.comA heightened focus on technology and efficiency gains over the past four years has allowed the oil and natural gas industry to return to profitability and recover from the deepest industry downturn in a generation. But not all of the industry changes have been positive. The new-look industry is producing record oil and natural gas with less than half the drilling rigs it needed four years ago.Read more on NewsOK.com